P2304Ignition System
Ignition Coil B Primary Control Circuit High
P2304 means the ECM detected high voltage on the primary control circuit for ignition coil B, indicating the coil is not switching as commanded.
🚗 Not recommended. A dead cylinder can damage the catalytic converter over time.
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🎯 Top Causes, Ranked by Likelihood
#1Failed ignition coil (cylinder B)$30-$120
Open or shorted primary circuit inside the coil.
#2Open or shorted coil wiring$40-$250
A break in the control wire or a short to power.
#3ECM driver circuit fault$200-$900
Failed coil driver inside the ECM.
🩺 Common Symptoms
- Single cylinder misfire
- Rough idle
- Check engine light
- Hesitation under acceleration
- Reduced power
💰 Repair Cost: DIY vs Shop
📋 Free OBD2 Code Cheat Sheet
The 50 most common codes with likely cause and DIY fix cost. Sent once, no spam.
🔧 How to Diagnose P2304
1Identify the cylinder for coil B on your engine
2Swap the coil to a nearby cylinder to see if the code moves
3Check the wiring for a short to power or an open
4Replace the coil if it is at fault
❓ Frequently Asked Questions
Can I drive with P2304?
Only briefly. A misfiring cylinder wastes fuel and risks catalytic converter damage.
What is the difference between P2303 and P2304?
P2303 is a low-voltage fault and P2304 is a high-voltage fault on the same coil B primary circuit.
How much does P2304 cost to fix?
Roughly $30-$150 DIY or $120-$400 at a shop.
🔗 Related Codes
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